Locking device for loading arm of drawing frame



Feb. 26, 1963 F. STAHLECKER 3,07

LOCKING DEVICE FOR LOADING ARM OF DRAWING FRAME Filed Feb. 28, 1961INVENTOR Z ma ma/t ATTORN E YO 3,078,520 LOCKING DEVICE FOR LOADING ARMF DRAWING FRAME Fritz Stahlecker, Geislingerstrasse 41, Bad Uberklngen,Wurttemberg, Germany Filed Feb. 28, 1961, Ser. No. 92,382 Claimspriority, application Germany Mar. 2, 1960 3 Claims. (Cl. 19-267) Thepresent invention relates to a locking device for locking the supportingand loading arm of the upper rollers of a drawing frame in a fixedposition so as to ma1ntain the springs under tension which areinterposed between the loading arm and the upper rollers and act uponthe latter and to prevent these springs from pivoting the loading armupwardly. The locking device according to the invention essentiallyconsists of a locking lever which extends along and acts upon aconsiderable part of the loading arm and is pivotably mounted on theloading arm at a point closely behind the pivoting axis of the loadingarm.

In locking devices for the supporting and loading arms of drawing framesit is known to provide small twoarmed levers with arms of approximatelyequal lengths, in which one arm serves as a pawl to engage into a recessin the locking member, while the other arm serves as an operating lever.Such locking devices have the disadvantage that, before the pawl can bedisengaged it must be released of its load, for example, by depressingthe loading arm.

It has therefore already been proposed to provide a longer operatinglever which is designed as a toggle lever and in which the short togglelink operates as a knee lever which iseither held under spring action oreffects the locking action by being placed in a position beyond thedead-center position. Such devices are, however, relatively expensive inproduction since they have to be made very accurately in order tofunction properly.

According to other prior proposals, in which long locking levers areprovided which are to operate without intermediate links, the loadingarm is to be connected to the rearwardly mounted loading spring by meansof the locking device. The locking device is in these constructionsmounted between the supporting rod and the drawing rollers whichrequires the loading arm to be made of a greater length which, in turn,means that the rear- Wardly mounted loading means have to be made of agreater strength.

It is an object of the present invention to overcome the above-mentioneddisadvantages by providing a onearmed angular locking lever and bypivotably mounting the same on the supporting and loading arm which theloading springs tend to pivot upwardly, and by providing the lockinglever with a locking member which engages upon a stationary abutmentwhich, when the loading arm is in the locked position, projects into thespace between the pivoting point of the locking lever on the loading armand the mentioned locking member. The side walls of the angular part ofthe locking lever which surround the side walls of the loading arm mayfor this purpose be provided with a pin which serves as the lockingmember and extends through an aperture in each side wall of the loadingarm. It is advisable to mount the loading arm directly on the supportingrod so as to be pivotable thereon, and to secure the loading arm in afixed axial position by means of a clamp which is secured to thesupporting rod and disposed between the side walls of the loading arm.This clamp has on its rear side a locking projection. The locking levermay be made of a weight sufiicient to maintain it in the lockingposition in which its locking pin, which is connected to the loading armby extending through the aperture in the side States Patent wallsthereof, presses upon the stationary locking projection on the clamp. Bylocking the loading arm in this manner, it will not as in previouslocking devices be necessary first to depress it beyond its operatingposition, which may be detrimental to delicate yarns.

The locking member may, however, also be designed so that the lockingaction is effected by friction by providing the apertures in the sidewalls in the form of elongated slots so that the locking lever can pivotto a certain extent relative to the loading arm and thereby engagefrictionally with the stationary projection on the clamp. The lockingaction may be further secured by providing the stationary lockingprojection with a groove into which the locking pin may engage in thelocked position so as to be held therein by the weight of the lockinglever.

The above-mentioned as well as additional features and advantages of theinvention will become more clearly apparent from the following detaileddescription thereof which is to be read with reference to theaccompanying sheet of drawings, in which FIGURE 1 shows a side view of aloading arm with the drawing'rollers which'are merely showndiagrammatically, and with the locking lever in the operative position:

FIGURE 2 shows an enlarged view of the clamping member for securing thelocking device by friction; while FIGURE 3 shows a similar view of aclamping member for positively securing the locking device.

In FIGURE 1 of the drawings, a supporting rod 1 carries the loading arm2 which is pivotably mounted thereon and consists of sheet metal bent toa U-shape. Loading arm 2 carries the upper drawing rollers 11 to whichit is connected by springs (not shown) which tend to pivot the loadingarm upwardly. A clamping member 3 is clamped by means of a bolt 4 uponthe stationary supporting rod 1 and is inserted between the two sidewalls 2" of loading arm 2 so that the latter is thus prevented fromsliding in the axial direction. A locking lever 5 which is likewiseU-shaped has downwardly extending side walls 5 surrounding the sidewalls 2' of loading arm 2 and it is pivotably connected to the latter bya pin 6. Locking lever 5 carries a pin 7 which extends through and isslidable along arcuate slots 7' in side walls 2' of loading arm 2 whenlever 5 is being pivoted. When loading arm 2 1s to be locked to preventit from being pivoted upwardly, locking arm 5 is pivotedcounterclockwise, whereby pin 7 engages upon the projection 8 on clampmgmember 3. The weight of locking arm 5 then mainturns it in the lockedposition. For unlocking it, it must merely be lifted by the handle onits front end. Pin 7 then slides off the projection 8, whereby theloading arm 2 s unlocked. If lever 5 is further pivoted in the clockwisedirection, pin 7 engages upon the end of slots 7' and thereby takesalong loading arm 2 so as to lift it together with the upper rollers 11oil the lower rollers. The head of clamping bolt 4 may also carry a leafspring 9 which ls bent so that when lever 5 is pivoted upwardly pin 6will slide over spring 9 and will then be arrested thereby to preventloading arm 2 from falling.

FIGURE 2 illustrates how the locking projection 8 on clamping member 3should be shaped to effect a frictional locking action. In the operativeposition, pin 7 engages into the rounded part 10.

FIGURE 3 shows a modification, in which the locking pro ection 8" onclamping member 3" is additionally provided with a groove 10' of anarcuate shape of a radius equal to that of pin 7. When lever 5 ispivoted downwardly to the locking position, pin 7 will first ride alongthe upper surface of locking projection 8" and will then engage intogroove 10' to be held therein.

Although the embodiments according to FIGURES 2 and 3 do not necessarilyrely upon the weight of lever 5 to eliect the locking action, the weightof the lever 5 is obviously available to render the locking action moresecure.

Although my invention has been illustrated and described with referenceto the preferred embodiments thereof, I Wish to have it understood thatit is in no way limited to the details of such embodiments, but iscapable of numerous modifications within the scope of the appendedclaims.

Having thus fully disclosed my invention, what I claim is:

l. in a drawing frame apparatus having upper rollers, a pivotablymounted loading arm for said upper rollers, said loading arm having sideWall portions, an angular one-armed locking lever extending along aconsiderable part of the length of said loading arm and pivotablymounted on said loading arm about an axis closely behind the pivotingaxis of said loading arm, a locking member secured to said lockinglever, a stationary member having a locking projection adapted toproject into a space provided between said axis of said locking leverand said locking member when said locking lever is pivoted to thelocking position, said locking member then engaging over said lockingprojection in locking engagement therewith.

2. Apparatus as defined in claim 1, wherein a part of said leveradjacent said axis is substantially U-shaped and includes side wallspartially surrounding said side wall portions of said loading arm, eachof said side Wall portions being provided with an aperture extendingtherethrough, and wherein said locking member comprises a pin secured tosaid side walls of said locking lever and extending through theapertures in said side Wall portions of said loading arm.

3. Apparatus as defined in claim 2, further comprising a stationarysupporting rod, said loading arm being substantially U-shaped andpivotably mounted on said supporting rod, and wherein said stationarymember is a clamping member clamped upon said supporting rodintermediate the side wall portions of said loading arm and preventingan axial movement of said loading arm, said clamping member having arear projection thereon forming said locking projection.

4. Apparatus as defined in claim 2, in which said locking projection hasa groove therein, said locking pin being adapted to engage into saidgroove and to be retained therein when said locking lever is pivoted toits locking position.

5. Apparatus as defined in claim 1, in which the weight of said lockinglever is sufficient to maintain said locking member in lockingengagement with said locking projection.

6. Apparatus as defined in claim 1, in which said locking member ismaintained in the locked position by frictional engagement with saidlocking projection.

7. Apparatus as defined in claim 1, in Which said locking member ismaintained in the locked position by being held in positiveinterengagement With said locking projection.

S. In a drawing frame apparatus, the combination of a pivotably mountedroller loading arm, a locking lever pivotably mounted about an'axisclosely behind the pivoting axis of said loading arm and adapted tooverlie a portion of said loading arm in the locking position thereof, alocking member secured to said locking lever, a stationary member havinga locking projection adapted to project into a space provided betweensaid axis of said locking lever and said locking member when saidlocking lever is pivoted towards the locking position thereof, and saidlocking member being in locking engagement with said locking projectionin the locking position of said locking lever.

References Cited in the file of this patent Dausch, German application1,056,980, printed May 6, 1959.

Kiibler, German application 1,062,589, printed July 30, 1959.

1. IN A DRAWING FRAME APPARATUS HAVING UPPER ROLLERS, A PIVOTABLYMOUNTED LOADING ARM FOR SAID UPPER ROLLERS, SAID LOADING ARM HAVING SIDEWALL PORTIONS, AN ANGULAR ONE-ARMED LOCKING LEVER EXTENDING ALONG ACONSIDERABLE PART OF THE LENGTH OF SAID LOADING ARM AND PIVOTABLYMOUNTED ON SAID LOADING ARM ABOUT AN AXIS CLOSELY BEHIND THE PIVOTINGAXIS OF SAID LOADING ARM, A LOCKING MEMBER SECURED TO SAID LOCKINGLEVER, A STATIONARY MEMBER HAVING